Commercialization in the meat-processing industry has emerged as one of the major agrobusiness challenges due to the large volume of wastewater produced during slaughtering and cleaning of slaughtering facilities. Slaughterhouse wastewater (SWW) contains proteins, fats, high organic contents, microbes, and other emerging pollutants (pharmaceutical and veterinary residues). It is important to first characterize the wastewater so that adequate treatment techniques can be employed so that discharge of this wastewater does not negatively impact the environment. Conventional characterization bulk parameters of slaughterhouse wastewater include pH, color, turbidity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), total suspended solids (TSS), total nitrogen (TN), total phosphorus (TP), and coliform counts. Characterization studies conducted have revealed the effects of the pollutants on microbial activity of SWW through identification of toxicity of antibiotic-resistant strains of bacteria. Due to the high-strength characteristics and complex recalcitrant pollutants, treatment techniques through combined processes such as anaerobic digestion coupled with advanced oxidation process were found to be more effective than stand-alone methods. Hence, there is need to explore and evaluate innovative treatments and techniques to provide a comprehensive summary of processes that can reduce the toxicity of slaughterhouse wastewater to the environment. This work presents a review of recent studies on the characterization of SWW, innovative treatments and technologies, and critical assessment for future research.

Sulphate-supplemented nitrogen, phosphorus and potassium (NPKS) fertilizer was nanoformulated through ionic gelation of chitosan (CS) and tripolyphosphate (TPP) at pH value of 5.5 to afford a series of nanofertilizers. The CS-TPP nanoparticles and CS-TPP-NPKS nanofertilizers were engineered using different dose of CS (0.125, 0.25, 0.5 and 1%) and NPKS fertilizer (20, 40 and 60 ppm). These nanoparticles were characterized through particle size distribution, zeta potential, SEM, XRD, FTIR, EDX and ICP-MS. The results revealed CS-TPP-NPKS particles with size range of 220–530 nm, polydispersity index (PDI) value between 0.2–0.5 and positive zeta potential. A preliminary evaluation of these nanoparticles along with inorganic NPK and NPKS fertilizers were conducted under greenhouse condition using maize (Zea mays L.) as a test crop. Findings from this study showed that inorganic NPKS (20:7:3:0.5) fertilizer, CS-TPP nanoparticles, and formulated NPKS nanofertilizers gave higher maize plants growth increases than NPK fertilizer and control treatments. The tallest plant (37.73 cm) and highest number of leaves (9) were recorded with the CS-TPP-NPKS nanofertilizer treatment obtained using 1% CS/NPKS (40 ppm). On the other hand, application of the nanoformulated derivative with 0.25% CS/NPKS (20 ppm) produced maize plants with superior chlorophyll content with 12.71 chlorophyll index value. A highly varied magnitude of the coefficient of variation in nutrient contents and uptake was recorded among the treatments. These results revealed that the incorporation of sulphur nutrient into NPK fertilizer and its transformation to nanoparticles have the potential characteristics for effective and productive growth of maize and sustainable agricultural activities.

Recent breakthroughs in agro-inputs research have led to the development of nanomaterials that can promote precision agriculture and better environmental security. The agricultural sector is increasingly facing the negative impacts of changing climates due to various stress conditions. To curb this scenario, economical and low-risk practices such as decreasing fertilizer inputs and seed priming have been promoted. In the current study, the H. odoratissimum aqueous extract was used to nucleate the Zn ionic species and grow the zinc oxide nanoparticles (ZnO NPs). The developed nanocomposites and their ionic zinc precursor were then integrated into tripolyphosphate (TPP)-crosslinked chitosan (CS/TPP) nanostructures by ionic gelation. Advanced physicochemical characterization techniques (SEM, EDS, TEM, DLS, FTIR, TGA, and XPS) were exploited to report the morphology, hydrodynamic size, surface charge, and structural organization of the developed nanomaterials. These revealed positively charged particles with hydrodynamic size in the 149–257 nm range. The NPs were used as priming agents for Zea mays seeds. At 0.04%, the ZnO-loaded CS/TPP NPs achieved higher root and shoot elongation in 10-day old seedlings compared to other treatments. The pristine CS/TPP NPs, Zn(II)-laden CS/TPP NPs, and ZnO-loaded CS/TPP NPs at 0.01% significantly promoted the early seedling development of seeds under salt stress. This represents the first report showing ZnO integrated chitosan nanocomposites as an auspicious nanopriming agent for stimulating the seed germination of maize. The study envisages offering perspectives on utilizing green nanotechnology to improve the early seedling development of maize. Furthermore, it has the potential to contribute towards UN SDG 2, thus addressing the threats to global food insecurity and doubling agricultural productivity by 2030.

This investigation reports the in situ growth of silver nanoparticles onto covalently bonded graphene oxide-chitosan, which serve as supported nanocatalysts for the NaBH₄ reduction of 2,4-dinitrophenol in aqueous systems. Fumaryl chloride reacted with chitosan in an acidic environment to yield a tailored polymeric material. The latter was, in turn, treated with the pre-synthesised graphene oxide sheets under acidic conditions to generate the GO-functionalised membrane (GO-FL-CS). The adsorption of Ag⁺ from aqueous media by GO-FL-CS yielded a set of membranes that were decorated with silver nanoparticles (Ag NPs@GO-FL-CS) without any reducing agent. Various analytical tools were used to characterise these composites, including Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller surface area analysis, X-ray diffraction, scanning electron microscopy/energy-dispersive X-ray analysis, inductively coupled plasma-mass spectrometry, and transmission electron microscopy. The silver-loaded materials were further used for the remediation of 2,4-dinitrophenol from aqueous solutions under batch operation. The BET analysis revealed that the functionalisation of GO with chitosan and Ag NPs (average size 20–60 nm) resulted in a three-fold increased surface area. The optimised catalyst (Ag mass loading 16.95%) displayed remarkable activity with an apparent pseudo-first-order rate constant of 13.5 × 10⁻³ min⁻¹. The cyclic voltammetry experiment was conducted to determine the nitro-conversion pathway. The reusability/stability test showed no significant reduction efficiency of this metal-laden composite over six cycles. Findings from the study revealed that Ag NPs@GO-FL-CS could be employed as a low-cost and recyclable catalyst to convert toxic nitroaromatics in wastewater.

Background: Dysphania ambrosioides (L.) Mosyakin & Clemants is an aromatic herb native to South America but also distributed widely throughout Africa and Europe. This plant is traditionally used to treat various ailments including pain and swellings, flu, parasitic diseases and is used as an analgesic, antipyretic, and wound healing. Phytochemical analyses of D. ambrosioides revealed the presence of terpenoids, flavonoids, coumarins, fatty acids, and miscellaneous compounds, among others, which might be responsible for its modern pharmacological actions.Objective: The present work summarizes recent developments on phytochemistry, ethnomedicinal use, pharmacology, and toxicity of D. ambrosioides. A critical assessment of the literature information of D. ambrosioides is also presented.Methods: The available information on D. ambrosioides was collected through libraries and electronic databases [Scifinder, ACS, Scielo, Science direct, Pubmed (National Library of Medicine), Wiley, Springer, PROTA, Web of Science, Google Web, Yahoo search and Google scholar] from respective inception until January 2021.Results: More than 150 compounds, including terpenoids, flavonoids, coumarins, fatty acids, and miscellaneous compounds, etc., were identified from D. ambrosioides. D. ambrosioides exhibited a wide range of pharmacological activities, including antimalarial, anti-inflammatory, antiparasitic, anticancer, insecticidal, antigiardial, among others. Metal nanoparticles synthesized from D. ambrosioides extracts presented enhanced pharmacological activities as compared to the crude plant extracts counterparts.Conclusion: D. ambrosioides is a promising medicinal plant, however, more in vivo experiments, cytotoxicity tests, and mechanisms of actions of its extracts and compounds are recommended to transubstantiate the ethnomedicinal claims of this plant into scientific rationale-based information.

Background: The liver is one of the crucial organs in humans and is responsible for the regulation of diverse processes, including metabolism, secretion, and detoxification. Ingestion of alcohol and drugs, environmental pollutants, and irradiation are among the risk factors accountable for oxidative stress in the liver. Plant flavonoids have the potential to protect the liver from damage caused by a variety of chemicals. Objective: The present study aims to summarize up-to-date information on the protective roles of plant flavonoids against liver damage. Methodology: The literature information on the hepatoprotective plant flavonoids was assessed through various databases, which were searched from their respective inception until March 2022. Results: More than 70 flavonoids with hepatoprotective activity against a variety of models of liver toxicity have been reported across the literature. Among these are flavones (19), flavonols (30), flavanones (9), isoflavonoids (5), and biflavonoids (2). Several hepatoprotective mechanisms of action were reported in various classes of flavonoids, including flavones and flavonols (upregulation of the pro-survival ERK1/2 pathway; downregulation of apoptotic proteins, including Bax, Bcl-2, Bax, BH3, caspase-3, 8, 9, etc.), flavanones (downregulation of NF-κB, TNF-α, IL-1 β, IL-6, iNOS, etc.), isoflavonoids (downregulation of lipogenesis genes, such as SREBP-1c, LXRα, RXRα, PPARγ and ACC2, with concomitant upregulation of genes involved in β-oxidation, including AMPK and PPARα; inhibition of CYPs, such as CYP1A1, CYP1A2, CYP2B1, CYP2D6, CYP2E1 and CYP3A1/2). Conclusion: The present work demonstrated the effectiveness of plant flavonoids against hepatic damage. However, more studies need to be performed regarding the cytotoxicity, pharmacokinetics, and mechanisms of action of these very important cytoprotective flavonoids.